Hybrid cars are known that use, as driving sources, an internal combustion engine and a motor driven by a power supply from a battery (refer, for example, to Patent Document 1). In the control device for the vehicle mentioned above, in order to achieve an improvement of a fuel efficiency of the internal combustion engine, “electric vehicle (EV) traveling” is carried out to make the vehicle travel by setting the internal combustion engine to a stop state and driving the motor.
Further, a water-cooled internal combustion engine is configured such that the engine is cooled by circulating cooling water within a water jacket that is formed in the cylinder head and the cylinder block. Further, the vehicle having such an internal combustion engine as a driving source is configured such that cooling water heated at a time of passing through the water jacket is fed to a heater core. Further, air delivery is carried out by a blower motor to the heater core, whereby hot air is generated by the heat of the cooling water of the heater core. Accordingly, heating of the passenger compartment is carried out.
In a vehicle provided with a water-cooled internal combustion engine and a motor, since heat accompanying combustion of the engine is not generated during EV travel, the cooling water is not heated, and the temperature of the cooling water is lowered gradually. Accordingly, if the temperature of the cooling water is lowered excessively, the ability to restart the internal combustion engine is hindered when EV travel is finished. Further, since hot air is not efficiently generated by the heater core, it is impossible to ensure a requested heating performance.
Accordingly, a conventional control device for a vehicle is configured to monitor the temperature of cooling water during EV travel and finish the EV travel to restart the internal combustion engine if the temperature of cooling water becomes equal to or less than a predetermined temperature, in order to limit excessive temperature reduction of the cooling water. Accordingly, it is possible to improve the ability to restart the internal combustion engine and to reliably ensure a requested heating performance.
Also, there has been known a vehicle provided with a seat heater that heats up seats in the passenger compartment by using power supplied by a battery as a heat source (refer to Patent Document 2). Further, a type of hybrid car has been developed that is provided with the seat heater mentioned above.